Short-Term Scleral Lens Wear Does Not Significantly Alter IOP

Short-term scleral lens wear does not result in significant intraocular pressure (IOP) increases, according to a study published in Eye & Contact Lens. While the lenses may result in initial scleral IOP increases, this increase is transient and subsides after 3.75 hours of wear, according to the report.

Researchers included 30 participants (73% women; mean age, 28 years) without a history of scleral lens wear in the prospective investigation. Study participants underwent random assignment to short-term scleral lens wear with lenses of either 15.6 or 18.0 mm diameters for 5 hours during 2 office visits. Scleral IOP was obtained after insertion and at 1.25 hour intervals for a total of 4 measurements. The team measured corneal IOP before insertion and following removal.

“[I]t is apparent that an increase in eye pressure does occur with scleral lens use in
some individuals under certain fitting conditions,” the study authors explain. “The individual susceptibility to an increase in eye pressure with scleral lens wear may correlate with overall susceptibility to the development of glaucoma. Therefore, it is imperative to identify and evaluate factors that may lead to an increase in intraocular pressure during scleral lens wear.”

Wearing the 15.6 mm and 18.0 mm diameter lenses both resulted in significantly higher scleral IOP 2.5 hours after lens insertion (mean 1.16 mm Hg; 95% CI, 0.54-1.78 and 1.37 mm Hg; 95% CI, 0.76-1.99, respectively), the report shows. However, these values were restored to baseline levels after 3.75 hours of wear and remained stable thereafter. Scleral lens size did not significantly affect IOP change, and similar changes were noted between the smaller and larger diameter lenses (P= .590). Corneal IOP was similar before insertion and following removal (P= .878).

“[T]he pressure exerted by a well-fitting scleral lens on the bulbar conjunctiva of a young and healthy eye is not sufficient to overwhelm regulatory mechanisms that exist to maintain equilibrium between the rate of aqueous production and drainage to maintain clinically acceptable levels of intraocular pressure,” according to the researchers.

Study limitations include a short duration, an inability to measure corneal IOP during scleral lens wear, and an overrepresentation of women in the study sample.